1. Field of the Invention
The present invention relates, in general, to the field of earth moving, and, in particular, to an earth-moving attachment for a vehicle.
2. Description of the Prior Art
In the field of earth moving, most jobs require specific equipment. For example, the formation of long trenches may require the use of a backhoe; whereas, backfilling may require a bulldozer. This specificity of requirements may make one article of earth-moving equipment so impractical for use in other areas of earth moving as to be nearly unusable except in the particular area for which it is designed. Accordingly, anyone who is required to perform a multiplicity of earth-moving jobs may be required to have access to a large variety of earth-moving equipment. Such a requirement may be quite expensive. Such a requirement may also prohibit a homeowner from performing certain tasks himself, and require him to employ an expensive company to carry out such tasks as landscaping or the like.
However, more serious than simply preventing a homeowner from performing certain tasks, is the drawback of preventing a single company from performing all tasks incident to a single larger job.
For example, in the roadbuilding art, graders are used for fine-grading relatively loose and level earth, and include a leveling blade mounted between the front and rear wheels of a vehicle. Graders are usually large and expensive as they must work large areas. Even though there are many designs intended to make graders more maneuverable with respect to such operations, graders may still not be maneuverable enough to be efficiently and practically applied to other jobs such as terracing or landscaping which might require intricate turns or other such close work.
Furthermore, most graders are large vehicles, and thus, efficient use of forces applied to the earth-moving blades may not be a serious problem, and since the blades of a grader are generally not changed, the ease with which a blade mounting can be changed may not be a primary consideration in the design of graders.
Still further, since the earth-moving blade of a grader is mounted between the front and rear wheels of the vehicle, the design of graders generally does not give primary consideration to whether or not the blades and the mounting therefor are being pushed or pulled.
As discussed above, many earth-moving jobs require an earth-moving blade to be moved along a path having intricate and tight turns and to work in a small area. Accordingly, the blade must be pushed in some locations, and pulled in others if the equipment is to be operated in an efficient manner. Still further, if the earth-moving equipment is to operate efficiently, the angle of attack between the earth-moving blade and the earth should be variable so the blade position can be altered to make most efficient use of the forces exerted by the vehicle which may be in a location relative to the blades dictated by the slope and contour of the terrain worked rather than in a position selected to most efficiently apply force to the blades.
All of the above-discussed drawbacks may prevent a grader from being used to efficiently work earth in many operations, such as excavating a trench adjacent to a road during preparation of that road, that are associated with road building, which is the primary function of a grader, as well as being applied to other areas, such as the preparation of terraces or tiered banks.
Accordingly, there are other forms of earth-moving equipment, such as plows, or the like, which are generally used to perform tasks requiring a high degree of maneuverability, such as cutting, turning and pulverizing soil in the preparation of furrows and various layers of earth elevations. Such devices are maneuverable, and can have the earth-moving blades easily changed and the angle of attack easily altered. Accordingly, earth-moving equipment such a plow, does not have the above-mentioned drawbacks associated with the lack of maneuverability of large equipment.
However, equipment, such as a plow, is generally not designed to permit the earth-moving blades to operate efficiently in several modes, nor are these blades generally designed to make the most efficient use of the forces applied thereto. Still further, equipment such as a plow, has sacrified its ability to efficiently perform jobs associated with graders and the like in order to efficiently perform other jobs. Accordingly, the problem of specificity is still present, albeit in a different form.
Neither graders nor plows are capable of efficiently pushing material in the manner of a bulldozer. Since many common jobs require the use of a bulldozer, a company or a homeowner may be required to either own a bulldozer or to hire one. In either instance, the cost in time and money is expensive and may be wasteful. However, even further than this, a bulldozer has its own shortcomings that detract from its overall adaptability and versatility. For example, since a bulldozer generally includes a single earth-moving blade, it generally cannot form certain types of terraces or the like in the most efficient manner, and the design of a bulldozer does not need to place primary emphasis on the efficient distribution of forces to and from the blade during use or in the attachment of the blade to the vehicle in a manner that permits easy and rapid movement of the angle of attack of the blade (other than the usual movement associated with the pushing of material) or its removal and replacement.
While none of the presently available earth moving-equipment is extremely versatile, such equipment is still not sufficiently adaptable to be modified to make it more efficient in carrying out jobs for which it was not designed. For example, a grader generally does not have means for readily adapting such device to perform jobs most efficiently performed by a plow.
Therefore, not only does present earth-moving equipment have drawbacks associated with the specificity of the equipment design vis a vis the variety of requirements associated with the earth-moving industry, such equipment has a further drawback in that it is not easily modified to be usable, even in a manner that is not most efficient, to perform jobs for which it was not primarily designed.
Accordingly, there is need for a device which is versatile and can be used for a wide variety of earth-moving jobs and can be used to adapt other earth-moving equipment to perform a greater variety of earth-moving jobs.